• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * bcm_ring.h : Ring context abstraction
4  * The ring context tracks the WRITE and READ indices where elements may be
5  * produced and consumed respectively. All elements in the ring need to be
6  * fixed size.
7  *
8  * NOTE: A ring of size N, may only hold N-1 elements.
9  *
10  * Copyright (C) 1999-2019, Broadcom.
11  *
12  *      Unless you and Broadcom execute a separate written software license
13  * agreement governing use of this software, this software is licensed to you
14  * under the terms of the GNU General Public License version 2 (the "GPL"),
15  * available at http://www.broadcom.com/licenses/GPLv2.php, with the
16  * following added to such license:
17  *
18  *      As a special exception, the copyright holders of this software give you
19  * permission to link this software with independent modules, and to copy and
20  * distribute the resulting executable under terms of your choice, provided that
21  * you also meet, for each linked independent module, the terms and conditions of
22  * the license of that module.  An independent module is a module which is not
23  * derived from this software.  The special exception does not apply to any
24  * modifications of the software.
25  *
26  *      Notwithstanding the above, under no circumstances may you combine this
27  * software in any way with any other Broadcom software provided under a license
28  * other than the GPL, without Broadcom's express prior written consent.
29  *
30  *
31  * <<Broadcom-WL-IPTag/Open:>>
32  *
33  * $Id: bcm_ring.h 700321 2017-05-18 16:09:07Z $
34  */
35 #ifndef __bcm_ring_included__
36 #define __bcm_ring_included__
37 /*
38  * API Notes:
39  *
40  * Ring manipulation API allows for:
41  *  Pending operations: Often before some work can be completed, it may be
42  *  desired that several resources are available, e.g. space for production in
43  *  a ring. Approaches such as, #1) reserve resources one by one and return them
44  *  if another required resource is not available, or #2) employ a two pass
45  *  algorithm of first testing whether all resources are available, have a
46  *  an impact on performance critical code. The approach taken here is more akin
47  *  to approach #2, where a test for resource availability essentially also
48  *  provides the index for production in an un-committed state.
49  *  The same approach is taken for the consumer side.
50  *
51  *  - Pending production: Fetch the next index where a ring element may be
52  *    produced. The caller may not commit the WRITE of the element.
53  *  - Pending consumption: Fetch the next index where a ring element may be
54  *    consumed. The caller may not commut the READ of the element.
55  *
56  *  Producer side API:
57  *  - bcm_ring_is_full  : Test whether ring is full
58  *  - bcm_ring_prod     : Fetch index where an element may be produced (commit)
59  *  - bcm_ring_prod_pend: Fetch index where an element may be produced (pending)
60  *  - bcm_ring_prod_done: Commit a previous pending produce fetch
61  *  - bcm_ring_prod_avail: Fetch total number free slots eligible for production
62  *
63  * Consumer side API:
64  *  - bcm_ring_is_empty : Test whether ring is empty
65  *  - bcm_ring_cons     : Fetch index where an element may be consumed (commit)
66  *  - bcm_ring_cons_pend: Fetch index where an element may be consumed (pending)
67  *  - bcm_ring_cons_done: Commit a previous pending consume fetch
68  *  - bcm_ring_cons_avail: Fetch total number elements eligible for consumption
69  *
70  *  - bcm_ring_sync_read: Sync read offset in peer ring, from local ring
71  *  - bcm_ring_sync_write: Sync write offset in peer ring, from local ring
72  *
73  * +----------------------------------------------------------------------------
74  *
75  * Design Notes:
76  * Following items are not tracked in a ring context (design decision)
77  *  - width of a ring element.
78  *  - depth of the ring.
79  *  - base of the buffer, where the elements are stored.
80  *  - count of number of free slots in the ring
81  *
82  * Implementation Notes:
83  *  - When BCM_RING_DEBUG is enabled, need explicit bcm_ring_init().
84  *  - BCM_RING_EMPTY and BCM_RING_FULL are (-1)
85  *
86  * +----------------------------------------------------------------------------
87  *
88  * Usage Notes:
89  * An application may incarnate a ring of some fixed sized elements, by defining
90  *  - a ring data buffer to store the ring elements.
91  *  - depth of the ring (max number of elements managed by ring context).
92  *    Preferrably, depth may be represented as a constant.
93  *  - width of a ring element: to be used in pointer arithmetic with the ring's
94  *    data buffer base and an index to fetch the ring element.
95  *
96  * Use bcm_workq_t to instantiate a pair of workq constructs, one for the
97  * producer and the other for the consumer, both pointing to the same circular
98  * buffer. The producer may operate on it's own local workq and flush the write
99  * index to the consumer. Likewise the consumer may use its local workq and
100  * flush the read index to the producer. This way we do not repeatedly access
101  * the peer's context. The two peers may reside on different CPU cores with a
102  * private L1 data cache.
103  * +----------------------------------------------------------------------------
104  *
105  * Copyright (C) 1999-2019, Broadcom.
106  *
107  *      Unless you and Broadcom execute a separate written software license
108  * agreement governing use of this software, this software is licensed to you
109  * under the terms of the GNU General Public License version 2 (the "GPL"),
110  * available at http://www.broadcom.com/licenses/GPLv2.php, with the
111  * following added to such license:
112  *
113  *      As a special exception, the copyright holders of this software give you
114  * permission to link this software with independent modules, and to copy and
115  * distribute the resulting executable under terms of your choice, provided that
116  * you also meet, for each linked independent module, the terms and conditions of
117  * the license of that module.  An independent module is a module which is not
118  * derived from this software.  The special exception does not apply to any
119  * modifications of the software.
120  *
121  *      Notwithstanding the above, under no circumstances may you combine this
122  * software in any way with any other Broadcom software provided under a license
123  * other than the GPL, without Broadcom's express prior written consent.
124  *
125  * $Id: bcm_ring.h 700321 2017-05-18 16:09:07Z $
126  *
127  * -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*-
128  * vim: set ts=4 noet sw=4 tw=80:
129  *
130  * +----------------------------------------------------------------------------
131  */
132 
133 #ifdef ____cacheline_aligned
134 #define __ring_aligned                      ____cacheline_aligned
135 #else
136 #define __ring_aligned
137 #endif // endif
138 
139 /* Conditional compile for debug */
140 /* #define BCM_RING_DEBUG */
141 
142 #define BCM_RING_EMPTY                      (-1)
143 #define BCM_RING_FULL                       (-1)
144 #define BCM_RING_NULL                       ((bcm_ring_t *)NULL)
145 
146 #if defined(BCM_RING_DEBUG)
147 #define RING_ASSERT(exp)                    ASSERT(exp)
148 #define BCM_RING_IS_VALID(ring)             (((ring) != BCM_RING_NULL) && \
149 	                                         ((ring)->self == (ring)))
150 #else  /* ! BCM_RING_DEBUG */
151 #define RING_ASSERT(exp)                    do {} while (0)
152 #define BCM_RING_IS_VALID(ring)             ((ring) != BCM_RING_NULL)
153 #endif /* ! BCM_RING_DEBUG */
154 
155 #define BCM_RING_SIZE_IS_VALID(ring_size)   ((ring_size) > 0)
156 
157 /*
158  * +----------------------------------------------------------------------------
159  * Ring Context
160  * +----------------------------------------------------------------------------
161  */
162 typedef struct bcm_ring {     /* Ring context */
163 #if defined(BCM_RING_DEBUG)
164 	struct bcm_ring *self;    /* ptr to self for IS VALID test */
165 #endif /* BCM_RING_DEBUG */
166 	int write __ring_aligned; /* WRITE index in a circular ring */
167 	int read  __ring_aligned; /* READ index in a circular ring */
168 } bcm_ring_t;
169 
170 static INLINE void bcm_ring_init(bcm_ring_t *ring);
171 static INLINE void bcm_ring_copy(bcm_ring_t *to, bcm_ring_t *from);
172 static INLINE bool bcm_ring_is_empty(bcm_ring_t *ring);
173 
174 static INLINE int  __bcm_ring_next_write(bcm_ring_t *ring, const int ring_size);
175 
176 static INLINE bool __bcm_ring_full(bcm_ring_t *ring, int next_write);
177 static INLINE bool bcm_ring_is_full(bcm_ring_t *ring, const int ring_size);
178 
179 static INLINE void bcm_ring_prod_done(bcm_ring_t *ring, int write);
180 static INLINE int  bcm_ring_prod_pend(bcm_ring_t *ring, int *pend_write,
181                                       const int ring_size);
182 static INLINE int  bcm_ring_prod(bcm_ring_t *ring, const int ring_size);
183 
184 static INLINE void bcm_ring_cons_done(bcm_ring_t *ring, int read);
185 static INLINE int  bcm_ring_cons_pend(bcm_ring_t *ring, int *pend_read,
186                                       const int ring_size);
187 static INLINE int  bcm_ring_cons(bcm_ring_t *ring, const int ring_size);
188 
189 static INLINE void bcm_ring_sync_read(bcm_ring_t *peer, const bcm_ring_t *self);
190 static INLINE void bcm_ring_sync_write(bcm_ring_t *peer, const bcm_ring_t *self);
191 
192 static INLINE int  bcm_ring_prod_avail(const bcm_ring_t *ring,
193                                        const int ring_size);
194 static INLINE int  bcm_ring_cons_avail(const bcm_ring_t *ring,
195                                        const int ring_size);
196 static INLINE void bcm_ring_cons_all(bcm_ring_t *ring);
197 
198 /**
199  * bcm_ring_init - initialize a ring context.
200  * @ring: pointer to a ring context
201  */
202 static INLINE void
bcm_ring_init(bcm_ring_t * ring)203 bcm_ring_init(bcm_ring_t *ring)
204 {
205 	ASSERT(ring != (bcm_ring_t *)NULL);
206 #if defined(BCM_RING_DEBUG)
207 	ring->self = ring;
208 #endif /* BCM_RING_DEBUG */
209 	ring->write = 0;
210 	ring->read = 0;
211 }
212 
213 /**
214  * bcm_ring_copy - copy construct a ring
215  * @to: pointer to the new ring context
216  * @from: pointer to orig ring context
217  */
218 static INLINE void
bcm_ring_copy(bcm_ring_t * to,bcm_ring_t * from)219 bcm_ring_copy(bcm_ring_t *to, bcm_ring_t *from)
220 {
221 	bcm_ring_init(to);
222 
223 	to->write = from->write;
224 	to->read  = from->read;
225 }
226 
227 /**
228  * bcm_ring_is_empty - "Boolean" test whether ring is empty.
229  * @ring: pointer to a ring context
230  *
231  * PS. does not return BCM_RING_EMPTY value.
232  */
233 static INLINE bool
bcm_ring_is_empty(bcm_ring_t * ring)234 bcm_ring_is_empty(bcm_ring_t *ring)
235 {
236 	RING_ASSERT(BCM_RING_IS_VALID(ring));
237 	return (ring->read == ring->write);
238 }
239 
240 /**
241  * __bcm_ring_next_write - determine the index where the next write may occur
242  *                         (with wrap-around).
243  * @ring: pointer to a ring context
244  * @ring_size: size of the ring
245  *
246  * PRIVATE INTERNAL USE ONLY.
247  */
248 static INLINE int
__bcm_ring_next_write(bcm_ring_t * ring,const int ring_size)249 __bcm_ring_next_write(bcm_ring_t *ring, const int ring_size)
250 {
251 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
252 	return ((ring->write + 1) % ring_size);
253 }
254 
255 /**
256  * __bcm_ring_full - support function for ring full test.
257  * @ring: pointer to a ring context
258  * @next_write: next location in ring where an element is to be produced
259  *
260  * PRIVATE INTERNAL USE ONLY.
261  */
262 static INLINE bool
__bcm_ring_full(bcm_ring_t * ring,int next_write)263 __bcm_ring_full(bcm_ring_t *ring, int next_write)
264 {
265 	return (next_write == ring->read);
266 }
267 
268 /**
269  * bcm_ring_is_full - "Boolean" test whether a ring is full.
270  * @ring: pointer to a ring context
271  * @ring_size: size of the ring
272  *
273  * PS. does not return BCM_RING_FULL value.
274  */
275 static INLINE bool
bcm_ring_is_full(bcm_ring_t * ring,const int ring_size)276 bcm_ring_is_full(bcm_ring_t *ring, const int ring_size)
277 {
278 	int next_write;
279 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
280 	next_write = __bcm_ring_next_write(ring, ring_size);
281 	return __bcm_ring_full(ring, next_write);
282 }
283 
284 /**
285  * bcm_ring_prod_done - commit a previously pending index where production
286  * was requested.
287  * @ring: pointer to a ring context
288  * @write: index into ring upto where production was done.
289  * +----------------------------------------------------------------------------
290  */
291 static INLINE void
bcm_ring_prod_done(bcm_ring_t * ring,int write)292 bcm_ring_prod_done(bcm_ring_t *ring, int write)
293 {
294 	RING_ASSERT(BCM_RING_IS_VALID(ring));
295 	ring->write = write;
296 }
297 
298 /**
299  * bcm_ring_prod_pend - Fetch in "pend" mode, the index where an element may be
300  * produced.
301  * @ring: pointer to a ring context
302  * @pend_write: next index, after the returned index
303  * @ring_size: size of the ring
304  */
305 static INLINE int
bcm_ring_prod_pend(bcm_ring_t * ring,int * pend_write,const int ring_size)306 bcm_ring_prod_pend(bcm_ring_t *ring, int *pend_write, const int ring_size)
307 {
308 	int rtn;
309 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
310 	*pend_write = __bcm_ring_next_write(ring, ring_size);
311 	if (__bcm_ring_full(ring, *pend_write)) {
312 		*pend_write = BCM_RING_FULL;
313 		rtn = BCM_RING_FULL;
314 	} else {
315 		/* production is not committed, caller needs to explicitly commit */
316 		rtn = ring->write;
317 	}
318 	return rtn;
319 }
320 
321 /**
322  * bcm_ring_prod - Fetch and "commit" the next index where a ring element may
323  * be produced.
324  * @ring: pointer to a ring context
325  * @ring_size: size of the ring
326  */
327 static INLINE int
bcm_ring_prod(bcm_ring_t * ring,const int ring_size)328 bcm_ring_prod(bcm_ring_t *ring, const int ring_size)
329 {
330 	int next_write, prod_write;
331 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
332 
333 	next_write = __bcm_ring_next_write(ring, ring_size);
334 	if (__bcm_ring_full(ring, next_write)) {
335 		prod_write = BCM_RING_FULL;
336 	} else {
337 		prod_write = ring->write;
338 		bcm_ring_prod_done(ring, next_write); /* "commit" production */
339 	}
340 	return prod_write;
341 }
342 
343 /**
344  * bcm_ring_cons_done - commit a previously pending read
345  * @ring: pointer to a ring context
346  * @read: index upto which elements have been consumed.
347  */
348 static INLINE void
bcm_ring_cons_done(bcm_ring_t * ring,int read)349 bcm_ring_cons_done(bcm_ring_t *ring, int read)
350 {
351 	RING_ASSERT(BCM_RING_IS_VALID(ring));
352 	ring->read = read;
353 }
354 
355 /**
356  * bcm_ring_cons_pend - fetch in "pend" mode, the next index where a ring
357  * element may be consumed.
358  * @ring: pointer to a ring context
359  * @pend_read: index into ring upto which elements may be consumed.
360  * @ring_size: size of the ring
361  */
362 static INLINE int
bcm_ring_cons_pend(bcm_ring_t * ring,int * pend_read,const int ring_size)363 bcm_ring_cons_pend(bcm_ring_t *ring, int *pend_read, const int ring_size)
364 {
365 	int rtn;
366 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
367 	if (bcm_ring_is_empty(ring)) {
368 		*pend_read = BCM_RING_EMPTY;
369 		rtn = BCM_RING_EMPTY;
370 	} else {
371 		*pend_read = (ring->read + 1) % ring_size;
372 		/* production is not committed, caller needs to explicitly commit */
373 		rtn = ring->read;
374 	}
375 	return rtn;
376 }
377 
378 /**
379  * bcm_ring_cons - fetch and "commit" the next index where a ring element may
380  * be consumed.
381  * @ring: pointer to a ring context
382  * @ring_size: size of the ring
383  */
384 static INLINE int
bcm_ring_cons(bcm_ring_t * ring,const int ring_size)385 bcm_ring_cons(bcm_ring_t *ring, const int ring_size)
386 {
387 	int cons_read;
388 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
389 	if (bcm_ring_is_empty(ring)) {
390 		cons_read = BCM_RING_EMPTY;
391 	} else {
392 		cons_read = ring->read;
393 		ring->read = (ring->read + 1) % ring_size; /* read is committed */
394 	}
395 	return cons_read;
396 }
397 
398 /**
399  * bcm_ring_sync_read - on consumption, update peer's read index.
400  * @peer: pointer to peer's producer ring context
401  * @self: pointer to consumer's ring context
402  */
403 static INLINE void
bcm_ring_sync_read(bcm_ring_t * peer,const bcm_ring_t * self)404 bcm_ring_sync_read(bcm_ring_t *peer, const bcm_ring_t *self)
405 {
406 	RING_ASSERT(BCM_RING_IS_VALID(peer));
407 	RING_ASSERT(BCM_RING_IS_VALID(self));
408 	peer->read = self->read; /* flush read update to peer producer */
409 }
410 
411 /**
412  * bcm_ring_sync_write - on consumption, update peer's write index.
413  * @peer: pointer to peer's consumer ring context
414  * @self: pointer to producer's ring context
415  */
416 static INLINE void
bcm_ring_sync_write(bcm_ring_t * peer,const bcm_ring_t * self)417 bcm_ring_sync_write(bcm_ring_t *peer, const bcm_ring_t *self)
418 {
419 	RING_ASSERT(BCM_RING_IS_VALID(peer));
420 	RING_ASSERT(BCM_RING_IS_VALID(self));
421 	peer->write = self->write; /* flush write update to peer consumer */
422 }
423 
424 /**
425  * bcm_ring_prod_avail - fetch total number of available empty slots in the
426  * ring for production.
427  * @ring: pointer to a ring context
428  * @ring_size: size of the ring
429  */
430 static INLINE int
bcm_ring_prod_avail(const bcm_ring_t * ring,const int ring_size)431 bcm_ring_prod_avail(const bcm_ring_t *ring, const int ring_size)
432 {
433 	int prod_avail;
434 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
435 	if (ring->write >= ring->read) {
436 		prod_avail = (ring_size - (ring->write - ring->read) - 1);
437 	} else {
438 		prod_avail = (ring->read - (ring->write + 1));
439 	}
440 	ASSERT(prod_avail < ring_size);
441 	return prod_avail;
442 }
443 
444 /**
445  * bcm_ring_cons_avail - fetch total number of available elements for consumption.
446  * @ring: pointer to a ring context
447  * @ring_size: size of the ring
448  */
449 static INLINE int
bcm_ring_cons_avail(const bcm_ring_t * ring,const int ring_size)450 bcm_ring_cons_avail(const bcm_ring_t *ring, const int ring_size)
451 {
452 	int cons_avail;
453 	RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size));
454 	if (ring->read == ring->write) {
455 		cons_avail = 0;
456 	} else if (ring->read > ring->write) {
457 		cons_avail = ((ring_size - ring->read) + ring->write);
458 	} else {
459 		cons_avail = ring->write - ring->read;
460 	}
461 	ASSERT(cons_avail < ring_size);
462 	return cons_avail;
463 }
464 
465 /**
466  * bcm_ring_cons_all - set ring in state where all elements are consumed.
467  * @ring: pointer to a ring context
468  */
469 static INLINE void
bcm_ring_cons_all(bcm_ring_t * ring)470 bcm_ring_cons_all(bcm_ring_t *ring)
471 {
472 	ring->read = ring->write;
473 }
474 
475 /**
476  * Work Queue
477  * A work Queue is composed of a ring of work items, of a specified depth.
478  * It HAS-A bcm_ring object, comprising of a RD and WR offset, to implement a
479  * producer/consumer circular ring.
480  */
481 
482 struct bcm_workq {
483 	bcm_ring_t ring;        /* Ring context abstraction */
484 	struct bcm_workq *peer; /* Peer workq context */
485 	void       *buffer;     /* Buffer storage for work items in workQ */
486 	int        ring_size;   /* Depth of workQ */
487 } __ring_aligned;
488 
489 typedef struct bcm_workq bcm_workq_t;
490 
491 /* #define BCM_WORKQ_DEBUG */
492 #if defined(BCM_WORKQ_DEBUG)
493 #define WORKQ_ASSERT(exp)               ASSERT(exp)
494 #else  /* ! BCM_WORKQ_DEBUG */
495 #define WORKQ_ASSERT(exp)               do {} while (0)
496 #endif /* ! BCM_WORKQ_DEBUG */
497 
498 #define WORKQ_AUDIT(workq) \
499 	WORKQ_ASSERT((workq) != BCM_WORKQ_NULL); \
500 	WORKQ_ASSERT(WORKQ_PEER(workq) != BCM_WORKQ_NULL); \
501 	WORKQ_ASSERT((workq)->buffer == WORKQ_PEER(workq)->buffer); \
502 	WORKQ_ASSERT((workq)->ring_size == WORKQ_PEER(workq)->ring_size);
503 
504 #define BCM_WORKQ_NULL                  ((bcm_workq_t *)NULL)
505 
506 #define WORKQ_PEER(workq)               ((workq)->peer)
507 #define WORKQ_RING(workq)               (&((workq)->ring))
508 #define WORKQ_PEER_RING(workq)          (&((workq)->peer->ring))
509 
510 #define WORKQ_ELEMENT(__elem_type, __workq, __index) ({ \
511 	WORKQ_ASSERT((__workq) != BCM_WORKQ_NULL); \
512 	WORKQ_ASSERT((__index) < ((__workq)->ring_size)); \
513 	((__elem_type *)((__workq)->buffer)) + (__index); \
514 })
515 
516 static INLINE void bcm_workq_init(bcm_workq_t *workq, bcm_workq_t *workq_peer,
517                                   void *buffer, int ring_size);
518 
519 static INLINE bool bcm_workq_is_empty(bcm_workq_t *workq_prod);
520 
521 static INLINE void bcm_workq_prod_sync(bcm_workq_t *workq_prod);
522 static INLINE void bcm_workq_cons_sync(bcm_workq_t *workq_cons);
523 
524 static INLINE void bcm_workq_prod_refresh(bcm_workq_t *workq_prod);
525 static INLINE void bcm_workq_cons_refresh(bcm_workq_t *workq_cons);
526 
527 /**
528  * bcm_workq_init - initialize a workq
529  * @workq: pointer to a workq context
530  * @buffer: pointer to a pre-allocated circular buffer to serve as a ring
531  * @ring_size: size of the ring in terms of max number of elements.
532  */
533 static INLINE void
bcm_workq_init(bcm_workq_t * workq,bcm_workq_t * workq_peer,void * buffer,int ring_size)534 bcm_workq_init(bcm_workq_t *workq, bcm_workq_t *workq_peer,
535                void *buffer, int ring_size)
536 {
537 	ASSERT(workq != BCM_WORKQ_NULL);
538 	ASSERT(workq_peer != BCM_WORKQ_NULL);
539 	ASSERT(buffer != NULL);
540 	ASSERT(ring_size > 0);
541 
542 	WORKQ_PEER(workq) = workq_peer;
543 	WORKQ_PEER(workq_peer) = workq;
544 
545 	bcm_ring_init(WORKQ_RING(workq));
546 	bcm_ring_init(WORKQ_RING(workq_peer));
547 
548 	workq->buffer = workq_peer->buffer = buffer;
549 	workq->ring_size = workq_peer->ring_size = ring_size;
550 }
551 
552 /**
553  * bcm_workq_empty - test whether there is work
554  * @workq_prod: producer's workq
555  */
556 static INLINE bool
bcm_workq_is_empty(bcm_workq_t * workq_prod)557 bcm_workq_is_empty(bcm_workq_t *workq_prod)
558 {
559 	return bcm_ring_is_empty(WORKQ_RING(workq_prod));
560 }
561 
562 /**
563  * bcm_workq_prod_sync - Commit the producer write index to peer workq's ring
564  * @workq_prod: producer's workq whose write index must be synced to peer
565  */
566 static INLINE void
bcm_workq_prod_sync(bcm_workq_t * workq_prod)567 bcm_workq_prod_sync(bcm_workq_t *workq_prod)
568 {
569 	WORKQ_AUDIT(workq_prod);
570 
571 	/* cons::write <--- prod::write */
572 	bcm_ring_sync_write(WORKQ_PEER_RING(workq_prod), WORKQ_RING(workq_prod));
573 }
574 
575 /**
576  * bcm_workq_cons_sync - Commit the consumer read index to the peer workq's ring
577  * @workq_cons: consumer's workq whose read index must be synced to peer
578  */
579 static INLINE void
bcm_workq_cons_sync(bcm_workq_t * workq_cons)580 bcm_workq_cons_sync(bcm_workq_t *workq_cons)
581 {
582 	WORKQ_AUDIT(workq_cons);
583 
584 	/* prod::read <--- cons::read */
585 	bcm_ring_sync_read(WORKQ_PEER_RING(workq_cons), WORKQ_RING(workq_cons));
586 }
587 
588 /**
589  * bcm_workq_prod_refresh - Fetch the updated consumer's read index
590  * @workq_prod: producer's workq whose read index must be refreshed from peer
591  */
592 static INLINE void
bcm_workq_prod_refresh(bcm_workq_t * workq_prod)593 bcm_workq_prod_refresh(bcm_workq_t *workq_prod)
594 {
595 	WORKQ_AUDIT(workq_prod);
596 
597 	/* prod::read <--- cons::read */
598 	bcm_ring_sync_read(WORKQ_RING(workq_prod), WORKQ_PEER_RING(workq_prod));
599 }
600 
601 /**
602  * bcm_workq_cons_refresh - Fetch the updated producer's write index
603  * @workq_cons: consumer's workq whose write index must be refreshed from peer
604  */
605 static INLINE void
bcm_workq_cons_refresh(bcm_workq_t * workq_cons)606 bcm_workq_cons_refresh(bcm_workq_t *workq_cons)
607 {
608 	WORKQ_AUDIT(workq_cons);
609 
610 	/* cons::write <--- prod::write */
611 	bcm_ring_sync_write(WORKQ_RING(workq_cons), WORKQ_PEER_RING(workq_cons));
612 }
613 
614 #endif /* ! __bcm_ring_h_included__ */
615